Second malignancy risk not elevated with RA biologic therapy

medwireNews: The use of biologic DMARDs for rheumatoid arthritis (RA) treatment is not associated with an increased risk for a second malignancy in patients with a history of cancer, Danish study findings indicate.

However, “no clear conclusion” can be reached regarding the mortality risk in this patient group, according to the poster presented at the 2017 ACR/ARHP Annual Meeting, held in San Diego, California, USA.

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Using data from the DANBIO rheumatology register and the Danish Cancer Registry, the team identified 1678 RA patients who were also diagnosed with a primary cancer between 2000 and 2011. Of these, 502 had received biologic agents either before, after, or both before and after the cancer diagnosis, while the remaining 1176 participants had never been treated with biologics.

After adjustment for age, sex, calendar year, and cancer site, patients who had received biologics did not have a significantly increased risk for developing a second neoplasm compared with never-users (nonsignificant hazard ratio [HR]=1.11). The results were similar when participants were stratified by when they had taken biologics, with no elevated risk for those who took biologics only before, only after, or at both timepoints relative to never users.

However, the data were less conclusive for the mortality risk. In the subgroup of 1315 patients with available information regarding the extent of the primary cancer, biologic-treated patients had a significant 1.35-fold higher mortality risk than those who had never received biologics after accounting for age, sex, calendar year, and cancer site. The association appeared to be driven primarily by the increased risk among those who had received biologics prior to the first cancer, with a significant adjusted HR of 1.53. But the statistical significance was lost after also adjusting for the extent of the primary cancer.

Lead author Lene Dreyer, from the University of Copenhagen, said in a press release that some RA patients with a history of cancer are potentially receiving inadequate treatment for their arthritis due to concerns regarding the development of a second malignancy or recurrences following biologic therapy.

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And although the study results must be interpreted with caution owing to the small numbers of patients who experienced a second malignancy, “our data does provide some reassurance that biologics don’t pose an immediate danger in patients with a history of cancer,” Dreyer concluded.